Abstract
Abstract We present an analysis of the 5–8 μm Spitzer-IRS spectra of a sample of 68 local ultraluminous infrared galaxies (ULIRGs). Our diagnostic technique allows a clear separation of the active galactic nucleus (AGN) and starburst (SB) components in the observed mid-infrared emission, and a simple analytic model provides a quantitative estimate of the AGN/SB contribution to the bolometric luminosity. We show that AGN are ∼30 times brighter at 6 μm than SBs with the same bolometric luminosity, so that even faint AGN can be detected. Star formation events are confirmed as the dominant power source for extreme IR activity, since ∼85 per cent of ULIRG luminosity arises from the SB component. None the less an AGN is present in the majority (46/68) of our sources.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Monthly Notices of the Royal Astronomical Society: Letters
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
